The criteria of justice for sustainability economics have not been specified and there is no clear guidance for choosing a particular theory of justice. Such criteria can refer to distributive, procedural, retributive or restorative justice, each of which leads to a different outcome. Baumgärtner and Quaas (2010a) do not concretize justice criteria. This, however, runs the risk that unsustainable criteria in unfair processes can be chosen. If one holds to the normative idea of sustainability, then the justice principles derived from theWorld Commission on Environment and Development — with its inter- and intra-generational principle and its overriding priority to serve the essential needs of today's poor — provide a sufficient starting point. A more concrete formulation of justice principles is given for example by Pearce (1987) in his attempt to couple ecological economics to Rawlsian principles of justice (Rawls, 1999 [1971]) with intergenerational considerations and thermodynamics. He concludes that sustainability as intergenerational fairness is achieved only by “ecologically bounded economies” (p. 17). This provides yet another argument, this time based on the justice dimension, for defining boundaries in which sustainable development paths are possible.